A seed maturation study was conducted to determine the earliest
date seed of subterranean clover (Trifolium subterraneum L.) may be
safely harvested without reduction in yield or seed quality. In 1981
and 1982, seed and bur weight, seed and bur moisture content, germination and seedling vigor were studied to determine...
A parasitic wasp, Trioxys pallidus Haliday
(Hymenoptera: Aphidiidae) was imported from Europe and
initially released against the filbert aphid Mvzocallis
coryli (Goetze) in hazelnut (filbert) orchards of the
Willamette Valley, Oregon beginning in 1984. In the
present study, I investigated the establishment rates of
this parasitoid. A total of 13...
Knowledge of post-dispersal seed fates and other regeneration characteristics is
crucial for predicting abundances and distributions of populations and, ultimately,
community species composition and diversity. Seed fate studies, however, are rare
primarily due to the difficulty of determining seed fates and causes of mortality.
This thesis investigated post-dispersal seed fates...
Montane meadows in the western Cascades of Oregon occupy approximately 5% of the landscape, but contribute greatly to the region's biodiversity. Western Cascades meadows are dynamic parts of the landscape and have contracted by over 50% in the past two hundred years in the HJ Andrews Experimental Forest (hereafter Andrews...
Relay strip-cropping combines two vegetation management tactics, under-sowing
and strip-management. In this study conducted from 1994 though 1997, a
cover crop seed-mixture containing oats (Avena sativa L. var. "Monida"), common
vetch (Vicia sativa L.), red clover (Trifolium pratense L.), annual ryegrass (Lolium
multflorum Lam.), and buckwheat (Fagopyrum esculentum Moench) was...